The following conditions may exist to be able to cause painful symptoms in the sacrum due to sedentary behavior: 1. The most common disease that can cause such symptoms is lumbar disc protrusion. The herniated lumbar disc is due to the protrusion of the cartilage structure between the lumbar vertebrae, which stimulates the surrounding soft tissues as well as the lumbar nerves, producing a series of symptoms such as back pain, leg pain and leg numbness. The lumbar spine nerves pass by the sacrum, and sedentary will inevitably aggravate the degree of lumbar disc protrusion, thus increasing the degree of nerve compression, causing pain in the sacral position and many patients with lumbar disc protrusion will have similar symptoms. 2, if there is damage or lesions in the sacroiliac joint, pain symptoms will also occur because of sedentary. The longer you stay seated, the more likely it is that the sacroiliac joint will separate and stretch due to body gravity, and the longer the time, the greater the possibility of local stimulation, and the more obvious the pain symptoms will be.